A deuteron and a proton moving with equal kinetic energy enter into to a uniform magnetic field at right angle to the field. If \( r_{d} \) and \( r_{p} \) are the radii of their circular paths respectively, then the ratio \( \frac{r_{d}}{r_{p}} \) will be \( \sqrt{x} : 1 \) where \( x \) is ________.
